<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
<script>
function Foo(){
    getName=function(){alert(1)}
    return this;
}
Foo.getName=function(){alert(2)}
Foo.prototype.getName=function(){alert(3)}
var getName=function(){alert(4)}
function getName(){alert(5)}
Foo.getName();  //2
getName();     //4
Foo().getName();  //1  全局执行getName=function(){alert(1)}
getName();   //1
new Foo().getName();  //3

</script>
</body>
</html>